Aseptic packaging of fluid food products



3,401,043 AsEPTIC PACKAGING OEFLUID FOOD` PRODUCTS Filed March 1s, 1965j 2 Sheets-Shee't 1 i im MNEMPW INVENTOH'S:

ROY D. FINLEY JAMES D. ELANIGAN ATTORNEYS,

R. D. FINLEY ET AL ASEPTIC PACKAGING OF FLUID FOOD PRODUCTS Sept. 10,1968 2 Sheets-Sheet 2 Filed March 18, 1955 N @I Nw g www# OE AO .M l. LB EmF .J VFOW 1 w N .D IIDSE W Y ER @mmv mzm #553 mwld m mk 5065,@ \Ommmm mv XE E @Em UnitedStates Patent O ASEPTIC PACKAGING OF FLUID FOODPRODUCTS Roy D. Finley and James D. Flanigan, Greenville, Ill., andEldred W. Bowen, Brentwood, Mo., assignors to Pet Incorporated, acorporation of Delaware Filed Mar. 18, 1965, Ser. No. 440,829 14 Claims.(Cl. 99-182) ABSTRACT OF THE DISCLOSURE A process of packagingaseptically a fluid food product in a flexible container wherein asupply of the containers are stacked in a chamber and sterilized withoxide ethylene gas, `the chamber is purged and filled with sterile airand the containers are filled alternately at filling stations with asterile fluid food product and then passed through a water trapcontaining bactericidal material. The filled container then has aportion of the contents heat sealed from the rest of the package andthis portion can be removed for testing without contaminating theremainder of the package.

This invention relates to a process of and apparatus for asepticallyfilling a sterile disposable package with a sterile food product. Thisinvention further relates to a flexible walled package containing asterile food product, and to a process of aseptically filling the same,and removing a sample portion without opening the sealed package.

Heretofore it has been impractical to fill a disposable flexible Walledpackage with a sterile fluid under aseptic conditions. While it iscommon to aseptically can liquids in sheet metal containers, the presentinvention provides a method of filling a sterile fluid food product intoa presterilized flexible walled container in an aseptic environment.

`The present invention specifically relates to the packaging of asterile ice cream mix into a flexible plastic bag which is filled underaseptic conditions. Many states have stringent laws restricting the saleof ice cream mix and similar products, and particularly restricting thetime which the products may be stored because of numerous spoilageproblems in the usual non-sterile product. The subject sterile productmay be stored for many months and lthe food product is still maintainedin sterile condition.

In commercial practice, it is essential to test sterile food products todetermine if the product is, in fact, sterile. A statisticallysignificant number of samples must be tested to give the resultsreliability. In a typical lot of 500, 30 to 60 should be examined tocomprise a significant number. Destructive' sampling of such a largefraction of the product is very expensive, particularly when theindividual packages are of large volume. Present testing methodsinherently requirethat the sterility of the packagerbe broken to make atest and thus expensive product is ruined. Accordingly another principalobject of the present invention is to provide a package containing asterile food product and a means for providing an attached removablerepresentative sample which, when detached, does not impair thesterility of the remainder of the product in the package or of thesample.

These and other objects and advantages of the present invention willbecome apparent hereinafter.

In the acompanying drawings herein like numbers refers to like partswherever they occur:

FIG. l is a diagrammatic respective flow diagram of the presentinvention;

FIG. la is similar to FIG. 1 but showing the chamber in greater detail;

FIG. 2 is similar to FIG.` 1 but showing a side View;

FIG. 3 is a perspective view of the sample food package;

FIG. 4 shows the sample portion detached;

FIG. 5 is a side view of the detached sample;

FIG. 6 is a plan view of a germ culture package used to test thesterility of the empty packages; and

FIG. 7 is an enlarged view of a pour spout with foil cover attached.

FIG. l is a flow diagram of the present process and the various stepsare set out in the blocks. Various details of the process steps will beexplained in greater detail hereinafter.

FIG. la shows the bags being stacked in the chamber which subsequentlyis sealed, serilized, vented, filled with sterile air, product contactsurfaces sterilized, and readied for operation. (FIG. 1) The separatelysterilized mix is passed to a timed switch valve 10 which delivers theproduct alternately to two filling nozzles 11 positioned in a sterileenclosed chamber 12. The sterile mix is passed to the valve 10 from apositive displacement pump (not shown) at a flow of approximately 6gallons per 26 seconds. The product is at a temperature of approximately80 F., the lower temperature being limited by the dew point within thechamber in order to avoid condensation on the surfaces of the pipes, andthe upper temperature being limited by the flash point of the productbeing filled. The valve 10 is timed to alternate approximately every 26seconds, since 6 gallon packages are conventionally filled in thechamber 12. The timing and delivery rate, of course, vary with the sizepackage being filled and the designed flow rate of the process. However,since the product is metered by a positive displacement pump it isimportant that the flow through the valve 10 not be interrupted.

The sterile mixture may be prepared by any conventional method accordingto the particular product and the type of sterilization conditionspreferred by the operator. Using an ice cream mixture, conventionalprocessing techniques are employed including mixing, standardization,preheating, HTST sterilization, and homogenization which involvesheating to about 300 F. for about 3.8 seconds. Other sterilizationtechniques f are satisfactory, and different conditions may be used forother food products.

The chamber 12 is provided with operator arm holes 13 to which areattached arm length rubber gloves 14 by means of which the operator canreach into the cha-mber 12 and manipulate a sterile bag 15.. The bags 15are stacked in the chamber 12 and the operator manually attaches thebags 15 to the lill nozzles 11. After a bag 15 is filled, the operatordetaches the bag 15 from the first filling nozzle 11 and moves it to aheat sealing as' sembly 16, where a seal is applied to the pour spoutopening on the bag 1S. This assembly is shown in copending Bowenapplication, Ser. No. 418,723 which is hereby incorporated into thepresent specication.

The operator then attaches another bag 15 to the first filling nozzle11, so that when the bag 15 attached to the second filling nozzle 11 hasbeen filled, the valve 10 will automatically switch the flowof fluidfrom the second fill nozzle 11 back to the first fill nozzle 11. Thesealed filled flexible container 15 is passed through a sterile trap 17onto a platform 18 and thereafter placed in a suitable paper boardshipping container. Y

The chamber 12 is maintained with a sterile environment by the passageof sterile air under about one-half to three inches of .pressure (water)and a temperature of about 60 to 80 F. The air is sterilized by heatingit to approximately 600 F. The air is cooled before it is passed to thechamber 12.

The liquid in the trap 17 is tap water having about fifty tofour-hundred parts per million of chlorine. This provides a'bactericidalliquid seal and insures sterility. Another advantage of the sterile trap17 is that sterile tools in sealed packages can be passed from outsidethe chamber 12 through the trap or lock 17 to the workman manning thegloves 14 to repair the inside of the chamber 12 without aecting itssterility. This is important, since it is difficult to sterilize thechamber 12 and this avoids much interruption of the process flow thatmight otherwise occur. The chamber 12 is provided in its lower most partwith an exhaust valve 20, which operates as a check valve and permitsany water or product which may accumulate in the chamber 12 to beexhausted.

The chamber 12 and bags 15 are pre-sterilized prior to operation. Asufficient supply of bags 15 is stacked in the chamber 12 through a door22 and germ culture packages 23 are interspersed in the stacks of bags15. The chamber 12 is free of moisture and doors are placed over thewater trap 17 and glove parts 13 prior to sterilization. Ethylene oxidegas or other suitable sterilizing gas is applied to the chamber 12 for 3to 15 hours (preferably 6 to 8) to sterilize the chamber 12 and itscontents, including the bags 15. A minimum lof 385 milligrams of pureethylene oxide per liter of contents (unit volume of container) is addedto the chamber 12. There is no free water in the ethylene oxide.Moisture in the form of dry steam is introduced into the chamber tomaintain 20 to 60% relative humidity and uniform chamber temperature ismaintained at 6() to 120 F. and preferably at 80 to 110 F. Withpolyethylene bags, 125 F. is about the maximum temperature, althoughwith polypropylene the gas can reach 250 F. The higher the temperature,the faster and more effective is the sterilization action of theethylene oxide.

The germ culture package 23 comprises filter paper having one millionbacterial spores per disc, and two discs per package 23 (the disc isabout 1/2 inch in diameter). The discs are sealed in a plastic bag whichis of the same material as the bags 15 to be filled. Approximately fivetest packets 23 are used per thousand bags 15. The bags are presumed tobe sterile when all bacterial spores in the test packets are killed.

Before the filling operation starts the chamber 12 is exhausted ofethylene oxide by pulling a 26-inch vacuum on -the chamber 12. The armhatches 13 and the water trap 17 are covered. After the ethylene oxideis exhausted, the chamber 12 is filled with sterile air. This cycle isrepeated again to assure all the ethylene oxide has been removed fromthe chamber 12. During filling, the sterile environment is maintained bythe flow of sterile air through the chamber 12 as hereinbeforediscussed.

The heat Sealers 16, the tape rolls 29, and the fill nozzles 11 areoperated by air cylinders which use` sterile air which is exhausted intothe chamber 12 to further insure sterility.

The preferred container 15 is of 4 mil polyethylene and is singlewalled. It has been found that double walled bags tend to inflate duringthe previously described evacuation and refilling process.

The seal 29 is of foil backed polyethylene.

Packages are randomly selected from each days production for statisticalevaluation of sterility. The packages are incubated for 72 hours at 80F., after which they are agitated by shaking and sampled as hereinafterdescribed.

The sample 19 is formed by applying a double heat seal to one corner ofthe bag. Thus, the sample portion 19 has a sealed edge 24 and the bag 15also has a sealed edge 25. To remove the sample 19, a cut is made (shownby the broken lines 26 in FIG. 3) between the sealed edges 24 and 25.Thus, a small. sealed sample representative of the entire contents ofthe primary package can be removed without impairing the integrity andvalue of the primary package. Thereafter a corner of the sample 19 issevered with a sterile hotY wire and the sample product can be removedwithout contamination for inoculation into nutrient broth with furtherincubation to determine sterility and for direct microscopicexamination.

Another advantage of the present package is that a reclosable feature isprovided, `so that the purchaser, after opening the saled package, canreclose it if all the product is not used immediately. The rigid pourspout 27 is provided withthreads 28 so that the purchaser, afterremoving the 'heat-sealed over-wrap 29 can apply `a screw cap to resealthe container 15. Other types of closures can be used, such assnap-caps, friction caps, etc.

Other forms of openings'in the containers 15 can be used instead of therigid pour spouts'27, valthough these are presently preferred. fA

In addition to ice cream mix, other fluid or semi-fluid food productswhich can be aseptically packed, such as milk evaporated milk, cream,fruit juice, tornato puree, etc., are siutable for use in the presentprocess.

Thus, lit is seen that the present invention provides aseptic fillingprocess and production which achieves all the objects and advantagessought therefore.

This invention is intended to cover all changes and modifications of theexamples of the invention herein considered for the purpose of thedisclosure and does not constitute departure from the spirit and scopeof the invention.

What is claimed is:

l. A process of packaging aseptically a fiuid food product including thesteps of:

(a) sterilizing flexible walled containers each having rigid pourspouts,

(b) maintaining a sterile filling environment,

(c) supplying a sterile, liuid food product continuously to the sterileenvironment,

(d) filling the sterile containers through thek pour spout, with thesterile food product, while maintaining the sterile environment,

(e) applying a fiuid tight seal to open end of the pour spout of thefilled container,

(f) exiting the filled sealed container from the sterile environmentthrough a trap filled with a bactericidal liquid without contaminatingthe sterile environment, and

(g) sealing off a segment of the filled container, thus trapping aportion of the containers contents without opening the container.

2. A process of packaging aseptically a fluid ice Cream productincluding the steps of:

(a) sterilizing flexible walled polyethylene containers of about 4 milthickness having rigid pour spouts attached thereto,

(b) maintaining` a sterile filling environment,

(c) metering a sterile ice cream mix continuously to the sterileenvironment,

(d) filling the sterile containers -with the ice cream mix whilemaintainingthe sterile environment,

(e) applying a fluid tight seal to the open end of the pour spout of thefilled container,

(f) exiting the filled `sealed container from the sterile environmentwithout contaminating the same, 1

(g) sealing off a segment of the `filled container, thus trapping aportion of the containers contents without opening the container, and

(h) removing the sealed off portion without contaminating the rest ofthe containers contents. f

3. A process of packaging aseptically a fluid product including thesteps of:

(a) placing fiexible walled plastic containers havin-g openings thereininto an enclosed chamber,

(b) filling the chamber with ethylene oxide to sterilize the container,

(c) purging the ethylene oxide with Sterile air,

(d) maintaining a sterile air filling environment in the chamber,

(e) supplying a continuous supply of sterile, fluid food product underpositive displacement fiow alternately to fill stations in the chamber,

(f) lfilling the sterile containers alternately at the fill stationswith the sterile food product, while maintaining the sterile airenvironment,

(g) moving the filled containers to a heat sealing apparatus in thechamber,

(h) applying a fluid tight heat sealed cover to the filled containeropenings, and

(i) exiting the filled sealed container from the chamber through aliquid seal filled with sterilizing fluid without contaminating thesterile environment of the chamber.

4. The process of claim 3 including the steps of sealing off a corner ofthe filled container, sealing off a segment of the filled container,thus trapping a portion of the containers contents Without opening thecontainer, and removing the sealed off portion without lcontaminatingthe rest of the containers contents.

5. A process of packaging aseptically a fluid food product including thesteps of:

(a) providing a supply of individual preformed unsterile collapsiblecommercial containers,

(b) sterilizing said containers at a sterilizing Station,

(c) maintaining a sterile filling environment,

(d) supplying a sterile, fluid food product to a filling station in thesterile environment,

(e) joining the sterile containers to the sterile food product supply atthe filling station,

(f) filling the sterile containers with the sterile food product, whilemaintaining the sterile environment,

(g) sealing the opening in the filled container through which thecontainer has been `filled to maintain sterility of the contents,

(h) exiting the filled sealed container from said environment through aliquid seal filled with sterilizing fluid without contaminating thesterile environment of the chamber.

6. The process of claim 5 wherein the containers are stacked incollapsed condition during sterilization.

7. The process of claim 6 wherein the containers are single wallpolyethylene of about 4 mil thickness.

8. The process of claim 5 including the step of stacking the containersin collapsed condition in the Sterile filling environment duringsterilization, and individually transferring the sterile Containers tothe -filling station.

9. The process of claim 5 wherein the filled container is passed througha water trap containing bactericidal material in exiting from thesterile environment.

10. The process of claim 5 including the steps of positioning thecontainers in stack `during sterilization, placing germ culture pack inthe stack and removing the pack to test the efficacy of thesterilization of the containers prior to filling the same.

11. The process of claim 5 including the Steps of supplying the sterilefluid food product to a plurality of filling stations in the sterileenvironment, and alternately filling sterilized containers at saidfilling Stations.

12. The process of claim S including the step of Sealing off a segmentof the filled container, thus trapping a p0rtion of the containerscontents.

13. The process of claim 5 wherein the fiuid food product is ice creammix.

14. The process of claim 5 including the step of supplying a postivetiow of sterile air to the filiing environment.

References Cited UNITED STATES PATENTS 3,020,689 2/1962 Luther 53-1403,063,845 ll/l962 Graves 99-171 3,105,335 10/1963 Hickey 53-127 RAYMONDN. I ONES, Primary Examiner.

S. DAVlS, Assistant Examiner.

